Reactor Kinetics & Fission 5 min read
Nuclear Fission & Criticality
k_eff = 1.0 · ²³⁵U + n → Ba + Kr + 2.43nSee why slow neutrons split U-235 500x better than fast ones, and how water moderators and boron rods keep a reactor steady.
Each 5-minute guide breaks down one core physical law with simple callout sketches, a quick mental-math example, and a live 60 FPS game to test it yourself.
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Illustrated Concept Guides
Core Physics Guides
Pick a concept below to see the sketch diagrams, formula breakdown, and interactive simulator.
Refraction & Photonics 5 min read
Snell's Law & Refraction
n₁ sin(θ₁) = n₂ sin(θ₂) · θ_c = arcsin(n₂/n₁)Use the two-wheel pavement-to-mud sketch trick to see why light bends in glass and how fiber optics trap beams past 41.8°.
Momentum & Impulse 5 min read
Conservation of Momentum
p = m·v · m₁u₁ + m₂u₂ = m₁v₁ + m₂v₂See why equal-mass billiard balls always split at 90° and why momentum stays conserved even in sticky crashes.
Reactor Control & Kinetics 6 min read
Moderators, Control Rods & Xenon-135
ΔE/E = 4A/(A+1)² · σ_a(Xe-135) = 2.65×10⁶ bDiscover why water slows fast neutrons in ~18 bounces, how Boron-10 rods soak up extras, and why Xenon-135 can lock a reactor after shutdown.
Fluid Mechanics 5 min read
Terminal Velocity & Air Drag
F_d = ½·ρ·v²·C_d·A · v_t = √(2mg / ρC_dA)Discover why doubling your falling speed quadruples air resistance, and compare terminal velocity on Earth, Mars, Titan, and the Moon.
Electromagnetism 6 min read
Ohm's & Kirchhoff's Laws
V = I·R · ∑ I_in = ∑ I_out · ∑ ΔV = 0Master voltage drop (ΔV = IR), current divider branches, and why taking a low-resistance copper path can fry a sensitive microchip.
Astrophysics 6 min read
Orbital Mechanics & Slingshots
F = GMm/r² · v² = GM(2/r - 1/a)See how flying behind a moving planet can add twice the planet’s orbital speed to your spacecraft for zero fuel.
Optics & Quantum 5 min read
Photoelectric Effect & Photons
E = h·ν = hc / λ ≥ E_gap (1240 / λ_nm)Understand Einstein’s photon energy formula, why wavelength controls electron conduction across band gaps, and how solar cells work.
Classical Mechanics 5 min read
Impulse & Impact Cushioning
J = F_avg · Δt = m · Δv ⟹ F_avg = Δp / ΔtSee why a 350ms cushioned catch produces 7× less impact force than a 50ms rigid stop for the exact same falling object.
Electromagnetism 6 min read
Joule Heating & RC Circuits
P = I²·R = V²/R · τ = R·C (63.2% V₀)See why P = I²R makes high current the #1 thermal enemy of microchips, and how τ = RC governs capacitor charging.